Redetermination of the phase equilibria in the system Sm-Co-Cu for Sm content 0–20 AT.% AT 850°C

摘要: Abstract A reinvestigation of the phase equilibria is carried out at 800°C in system Sm-Co-Cu for Sm content up to 20 at.%. The experimentation involves electron microanalysis and X-ray diffraction study heat-treated specimens some DTA. new features exhibited are, on binary Sm-Co limit, existence compound Sm5Co19 with rhomboedral structure, Sm-Cu boundary, solid state decomposition SmCu5 forming SmCu6 a Sm2Cu9 not previously identified, about 850°C. In Cu-rich part system, pseudobinary Sm(Co1−xCux)5 hexagonal CaCu5 structure type shown have an range extended towards Sm-deficient compositions. lattice parameters indicate that stoichiometry departure likely results from disordered substitution Cu or Co atom pairs atoms Sm(Co1−xCux)5.